<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * A Date MIME Header for Swift Mailer.
 *
 * @package    Swift
 * @subpackage Mime
 * @author     Chris Corbyn
 */
class Swift_Mime_Headers_DateHeader extends Swift_Mime_Headers_AbstractHeader
{
	/**
	 * The UNIX timestamp value of this Header.
	 *
	 * @var int
	 */
	private $_timestamp;

	/**
	 * Creates a new DateHeader with $name and $timestamp.
	 *
	 * Example:
	 * <code>
	 * <?php
	 * $header = new Swift_Mime_Headers_DateHeader('Date', time());
	 * ?>
	 * </code>
	 *
	 * @param string $name of Header
	 * @param Swift_Mime_Grammar $grammar
	 */
	public function __construct($name, Swift_Mime_Grammar $grammar)
	{
		$this->setFieldName($name);
		parent::__construct($grammar);
	}

	/**
	 * Get the type of Header that this instance represents.
	 *
	 * @see TYPE_TEXT, TYPE_PARAMETERIZED, TYPE_MAILBOX
	 * @see TYPE_DATE, TYPE_ID, TYPE_PATH
	 *
	 * @return int
	 */
	public function getFieldType()
	{
		return self::TYPE_DATE;
	}

	/**
	 * Set the model for the field body.
	 *
	 * This method takes a UNIX timestamp.
	 *
	 * @param integer $model
	 */
	public function setFieldBodyModel($model)
	{
		$this->setTimestamp($model);
	}

	/**
	 * Get the model for the field body.
	 *
	 * This method returns a UNIX timestamp.
	 *
	 * @return mixed
	 */
	public function getFieldBodyModel()
	{
		return $this->getTimestamp();
	}

	/**
	 * Get the UNIX timestamp of the Date in this Header.
	 *
	 * @return int
	 */
	public function getTimestamp()
	{
		return $this->_timestamp;
	}

	/**
	 * Set the UNIX timestamp of the Date in this Header.
	 *
	 * @param integer $timestamp
	 */
	public function setTimestamp($timestamp)
	{
		if (!is_null($timestamp)) {
			$timestamp = (int)$timestamp;
		}
		$this->clearCachedValueIf($this->_timestamp != $timestamp);
		$this->_timestamp = $timestamp;
	}

	/**
	 * Get the string value of the body in this Header.
	 *
	 * This is not necessarily RFC 2822 compliant since folding white space will
	 * not be added at this stage (see {@link toString()} for that).
	 *
	 * @see toString()
	 *
	 * @return string
	 */
	public function getFieldBody()
	{
		if (!$this->getCachedValue()) {
			if (isset($this->_timestamp)) {
				$this->setCachedValue(date('r', $this->_timestamp));
			}
		}

		return $this->getCachedValue();
	}
}
